Quick margin release assembly for typewriters



Dec.. 16, 1958 J. T. CARLSON QUICK MARGIN RELEASE ASSEMBLY FOR TYPEWRITERS Filed Feb. 18. 1954 3 Sheets-Shea?l 1 Mamani INVENToR: JOHN T CARLSON N Nm V4.

Dec. 16, 1958 J, cARLsoN 2,864,483

QUICK MARGIN RELEASE ASSEMBLY FOR TYPEWRITERS Filed Feb. 18. 1954 3 Sheets-Sheet 2 ,o m 3 9 'I 2 INVENTolc JOHN 'l'. CARLSON BY ATT'Ys Dec. 16, 1958 .1.1'. CARLSON QUICK MARGIN RELEASE ASSEMBLY FOR TYPEWRITERS Filed Feb. 18, 1954 3 Sheets-Sheet 3 INVENTOR: lJOHN T CAR LSON BY United States PatentO ice 2,864,483 PatentedlDec.` 16,A

QUICK MARGIN RELEASE ASSEMBLY FIOR TYPEWRITERS John T. Carlson, Grand Rapids, Mich., assignor to R. C. Allen Business Machines, Inc., Grand Rapids, Mich., a corporation of Michigan Application February 18, 1954, Serial No. 411,063

15 Claims. (Cl. 197-63) This invention relates to margin stop mechanism for effecting quick operation of the right and left hand margin stops so that the typist or operator may quickly and readily set the margins required for typing on the paper by first setting the carriage in a predetermined position and then causing the margin stop mechanism or assemblies to be set automatically upon the depression of a key.

The margin stop mechanism of the present invention comprises margin stop assemblies for setting the margins at the right and left hand sides of the carriage so that the operator may bring the margin for the printed type on a sheet of paper to a predetermined exact position on the left hand side, also to set the right hand margin as the carriage moves to the left upon depression of the type keys. The margin assemblies are mounted on a dentated bar, being maintained in position, or released for movement by margin stop control rails controlled by the operation of margin set keys. Both the right and left hand margin stop assemblies are mounted on a single dentated or rack bar and are moved to margin stop position by tension coil springs when the margin set keys are operated. There is one spring for each margin stop assembly so as to provide proper movement of the margin stop assemblies when the margin set key is operated and at the same time provide soft, flexible, resilient operation.

A cross member is arranged behind the paper table (forwardly of the operator) in such a manner that certain sight tabs on the margin stops are visible above the paper table and cooperate with a scale on the cross member to permit the operator to see at a quick glance exactly where the margin stops are set. The control rails, which control the operable positions of the margin stops, are provided with inclined slots through which pins pass to effect proper operation when the control rails are operated to permit movement of the margin stop members. The control rails are operated by finger pieces or keys for shifting the control rails. The finger pieces or keys are positioned adjacent the outer sides of the carriage to permit quick and easy operation. Shiftable members, in the nature of depressible keys, are also arranged adjacent the control rail keys and are also located in a position adjacent the outer sides of the carriage to release the carriage escapement mechanism so that the carriage will be slidable freely when the escapement keys are depressed. The keys for operating the control rails, and the keys for releasing the escapement are arranged side-by-side and in close juxtaposition so that both of said keys may be depressed or operated by a single finger. The positioning of the carriage to bring the margin stops to the point of margin setting, and the actual shifting of the margin stop assemblies, is therefore accomplished by the operator effecting both operations by pressing both keys with one nger.

The primary object of the present invention resides in the provision of a member having a scale visible to the operator, in conjunction with tabs extending from the margin stops, and visible by the operator, the tabs extending above the paper table and arranged Vimmediately forward of the scale (in-front of the operator) so that the operator may see at a quick glance the exact position of the margin stops. i

Another important object of the invention is the arrangement of escapement keys positioned immediately adjacent the margin control rail keys to permit the keys of both mechanisms to be operated by one finger.A

Another object resides in the provision of margin control rails eachhaving inclined slots adjacent their outer ends, the said slots receiving stationary pins to effect av movement of the control rails when the control rail Vkeys are shifted; spring means may be provided toL return the control rails to original position after said shifting operation.

Still another object of the invention consists in the provision of new and novel margin .stop assemblies which are mounted on asingle bar and operated by separate 'independent tension coil springs to effect positive but still soft, flexible,vnoisele`ss operation.

A further object of the invention consists in the arrangement of margin stop assemblies to permit manual, as well as automatic, operation thereof, the assemblies having projecting ends extending a predetermined distance above the paper table for easy visibility with respect to a scale arranged on a member in front of the` paper table and with respect to the lateral paper guide which guides the left hand edge of a sheet of paper.

A still further object consists in theprovision of margin release assemblies which are adapted to be moved toa predetermined position upon the depression of a margin set key, the assembly `being composed of various parts to release the detent from the milled slots in a rack bar by a manual operation, there also being improved means normally to maintain the detent in a slot or groove but automatically released from detented position upon the operation of a margin set key.

Still another object resides in the' construction and arrangement of parts to effect quickand easy operation; of the various elementsto permit certain ofthe parts to be quickly viewed with respect to other parts to provide a structure which operates efficiently, positively and silently, and which is so constructed and arranged as to not be likely to get out of order, thereby requiring exceedingly little or no service.

Numerous other objects and advantages will be apparent throughout the progress of the specification which follows.

The accompanying drawings illustrate a selected einbodiment of the invention and the views therein are as follows:

Fig. 1 is a detail front elevational view of a ntype-H writer carriage with which the invention is embodied;

Fig. 1A is a detail transverse sectional view on the line lA-lA of Fig. 1, certain parts being omitted for the sake of clearness;

Fig. 2 is a rear elevational view showing the margin stop assemblies mounted on a rack bar, said View looking in the direction of the arrows 2 2 of Fig. l;

Fig. 3 is a detail perspective view of a fixed mounting bar to which the margin stop control rails are mounted;

Fig. 4 is a detail front elevational view of the mechanism showing the parts in their normal operative or rest position, said view looking in the direction of the arrows 4-4 of Fig, 7;

Fig.v 5 is a View similar to Fig. 4 showing the position a margin stop control rail assumes when the right handV dentated bar, and the spring means for causing the margin stop assemblies to be shifted;

Fig. 7 is a detail top plan view of the structure disclosed in Fig. 2; and

Fig. 8 is a detail transverse sectional view on-the line s-s of Fig. 7.

The particular construction herein disclosed, for illustrating the improved margin stop mechanism of the invention, is shown as applied to the well-known Visomatic typewriter as made by the R. C. Allen Business Machines, Inc. of Grand Rapids, Michigan.

The margin stop mechanism of the invention is mounted on a slidable carriage 1, Fig. 1, and includes the usual type roller 2 `and a spring-urged paper holder bail 3. A paper table 4 is arranged immediately behind (forwardly of the operator) the roller 2 and holds the paper in the usual manner, there being a laterally movable paper guide 5 operating in a horizontal longitudinally extending guide slot for guiding the left hand edge of a sheet of paper. The paper table 4 is pivotally mounted at its ends and is spring-pressed to normally hold it in proper operating position. It is free, however, to be moved manually a predetermined distance against the tension of a spring. The paper table 4 is provided with scales 6, 6 at its left hand end and at its right hand end as shown in Fig. l. The left scale reads from the left to right and the right scale reads from right to left. Each scale is provided with graduations equal to the spacing of letters or spaces and carries indicia depicting inches. In the particular embodiment shown in Fig. 1, there are ten graduations to indicate the number of spaces or letters to the linear inch of typing.

. A member 7, Figs. l and lA, is secured to the carriage 1, between the end brackets thereof, and is positioned immediately behind the paper table or holder 4 extending a predetermined distance above the top of the holder. A scale 8 is provided on the front face of the fixed member 7, and this scale is positioned above the top of the holder 4 so as to be readily visible to the operator. The scale comprises graduations 9, each graduation being equal to the space of a type letter yor type space, there being ten such graduations to the linear inch. The graduations are arranged in units of ten, being numbered from naught to ninety as indicated at 10, Fig. l. Ninety-five such graduations 9 actually are shown, Fig. 1. The scale 8, including the graduations 9 and the numeral indicia 10, is used in connection with certain tabs or extensions on the margin stop assemblies,

the tabs and scale being visible by the operator, so that the operator will know at a quick glance the exact position of the margin stops. The purpose of these tabs and the scale 10 will be described later.

4 A rackbar 11, Fig. 2, is arranged rearwardly of the paper holder 4 and this rack bar is`provided with milled slots providing alternate spaced slots and teeth. The spaces between teeth are equivalent to the spacing of type characters. The rack bar 11, which is also` frequently referred to as a dentated bar, is rigidly secured to end plates 12 on the frame of the carriage 1. A right hand margin stop assembly 14, and a left hand margin stop assembly 13, are slidably mounted along the rack bar 11 and provide stops for limiting both the right hand and left hand movement of the carriage so that the carriage will be caused to stop precisely at the proper place to bring impressions of the type characters into proper vertical Valignment on the sheet.

'The left hand margin stop assembly 13 (to the right, Fig. 2 and to the left, Figs. 4, 5 and 6) is connected at 15 to an elongated coil tension spring 16. The coil tension spring 16 is trained about a pulley 17 which is connected to a rigid bracket 18. The free end of the spring is fastened to a pin 19 on a bracket 20, Figs. 4 and 5. The spring 16 normally urges the margin stop assembly 13 to the left, Fig. 2, and to the right, Figs. 4 and 5.

The right hand margin stop assembly 14, Figs. 4 and 5, is connected at 21 to an elongated coil tension spring 22 which passes around a pulley 23 mounted on the fixed bracket 20. The free end of the coil tension spring 22 is connected at 24 to the bracket 18.

The right hand assembly 14 moves to the right, Fig. 2 (to the left, Figs. 4 and 5), when its detent is out of engagement with a slot of the rack bar 11. Also when the left hand margin stop assembly 13 has its detent out of engagement with the rack bar 11, the spring will pull this assembly to the left, Fig. 2 (to the right, Figs. 4 and 5).

Each assembly, 13 and 14, carries a spring-urged detent 25 which is adapted to be received in a slot in the rack bar depending upon the position in which the margin stop assembly is positioned. Each detent 25 is springurged so as to normally keep the detent 25 in its engaged position in a slot in the rack bar 11. However, when a detent is out of engagement with a slot in the rack bar 11, the margin stop assembly 13 or 14 is adapted to be pulled to the respective sides of the machine (normally inwardly). Each detent 25, Fig. 4, comprises an end tooth-like portion extending downwardly from a lever arm 26 which is pivotally mounted at 27 to a channelshaped shoe 28 which receives the rack bar 11. The end of the lever arm 26 has a roller 29 pivotally connected thereto which is adapted to be engaged by a control rail 30 or 31. The front margin stop control rail 30 controls the operation of the assembly 14 while the rear margin stop control rail 31 controls the operation of the margin stop assembly 13, Figs. 4 and 5.

The front margin stop control rail 30, which controls t :the right hand margin stop 14, is normally urged upwardly to permit its detent 25 to be received in a slot in the rack bar 11. When the control rail 30 is shifted, the lower end of this control rail will depress roller 29 on the margin stop assembly 14 and thus permit the margin stop 14 to be pulled inwardly to the left, Figs. 4 and 5, by the tension coil spring 22.

The front control rail 30 is mounted on a fixed mounting bar 32 which is arranged forwardly of the control rail 31, as well as forwardly and above the rack bar 11.

. The front control rail 30 is provided, at its left end, Figs.

4 and 5 (to the right, Fig. 2), with an elongated inclined slot 33 which receives a pin 34 on the xed mounting bar 32. Near the opposite, or right hand, end of the front control rail 30, there is provided an elongated inclined slot 35 which receives a pin 36 xed to the opposite end of the mounting bar 32. The outer right hand the key 38, the final result being the same, the front control rail 30 will be moved inwardly (to the left) as well as downwardly. The downward movement ol" the front control rail 30, Fig. 5, depresses the roller 29, Fig. 6, on the arm 26 of the margin assembly 14, and swings the arm 26 on its pivot 27 to permit its detent 25 to be raised upwardly.

i The rear margin stop control rail 31, Figs. 4 and 5, which controls the left hand margin stop 13, is normally urged upwardly to permit its detent 25 to be received in a slot in the rack bar 11. When the rear control rail u 31 is shifted, the lower end of the rear stop control rail 31 will depress a roller 29 on the margin stop assembly 13 and thus permit the margin stop 13 to be pulled inwardly to the right by the tension coil spring 16,

The rear control rail 31 is provided, at its right end, Fig. 4 and 5, with an elongated inclined slot 39 which receives the pin 36 on the fixed mounting bar 32. The opposite end of the rear control rail 31 is provided with an elongated inclined slot 40 which receives the pin 34 fixed to the opposite end of the mounting bar 32. The

pins 34 and 36 are received in the slots in the ends of both rails 30 and 31. The outer end of the rear control rail 31 has its left end extended in the form of a key lever 41 to which a key 42 is mounted at the upper end thereof. Thus when the key 42 is shifted, either by pushing inwardly or depressing, the rear control rail 31 will be moved inwardly (to the right, Fig. 4) as Well as downwardly. The downward movement of the rear control rail 31 will cause the arm 26, Fig. 6, of the margin stop assembly 13 to be swung on its pivot 27 and thus permit the detent 25 to be raised upwardly.

The front control rail 30, and the rear control rail 31, are connected together by a spring 43, Fig. 2, which urges the control rails in opposite directions with the slots at their ends contacting respective pins which are fixed on the mounting bar 32. The spring 43, therefore, normally urges the control rails 30 and 31 into their upward normal position, permitting each detent to remain in a slot in the rack or dentated bar 11.

The Velongated inclined slots incontrol rails and 31 adjacent the o-uter ends thereof, Lcooperate with fixed pins 34 and 36 and provide an exceedingly simple, positive and easy operating .means to control the operation of the margin stop assemblies 13 and 14. Aside from the economical manner in which the control rails are made, there is the factor of ease in assembly as well as assuring easy, effective, positive operation. Also, the construction of the rails is such that they will fit into a small space, requiring no expensive machining oper-ations, and permitting operation either by being pushed inwardly or by being depressed. Also if operation in a reverse manner should be required for any purpose, the slots may be reversed.

The margin stop assemblies 13 and 14, while positioned oppositely to each other, comprise the same identical parts except they areoppositely disposed. Therefore, only one assembly will be described. The assembly 14 has been selected to be described and the various parts are shown 4separately in the exploded view of Fig. 6. The arm 26 of an assembly is pivoted to the shoe 28 as indicated at 27 in the manner previously described. An arm 44 has its base 45 connected to the rear surface 46 of the shoe 23. A second arm 47 is pivotally connected xby a pin 4S to the arm 44. The pin 48 passes through the holes 49 and Sil respectively in the arms 44 and 47. The arm 44 has an integral ear 51 bent therefrom and is disposed opposite the integral ear 52 on the arm 47. The ears 51 and 52 each carry a pin 53 to support a coil expansion spring 54 normally to hold the arms 44 and 47 apart and maintain the detent 25 in position. The arm 47 carries an inturned flange or lip 55 which is adapted to extend beneath a part of the detent arm 26, and thus nor mally hold the detent 25 in its engaged position with a slot in the rack bar 11. When the ears 51 and 52 are pressed together, the arm 47 will swing on its pivot pin 48 and raise the lip S5 upwardly to cause the forward end of the arm 26 to be raised and lift the detent 25 out of engagement with a slot in the rack bar. The squeezing together of the arms 44 and 47 releases the detent 25 and permits the assemblies to be slid manually along the rack bar 11. Also the operation, or the depression of a key 38 or 42, will cause the detent 25 to beraised out of a slot whereupon a coil tension spring will move the margin stop assembly 13 or 14 to proper adjusted position because of the pressure of a control rail 30 or 31 against` a rollerl 29. The assemblies 13 and 14 are operated manually o-r they may be operated automatically by their respective springs upon the depression of a respective margin set key 38 or 42.

The settings of the margin stop assemblies are determined by a stop member in the form of a margin vblock Iand release assembly 56 which is operated by a margin release key. The right hand margin release assembly 14 (at the left, Fig. 2) includes an extension 57 to control the carriage escapement which actuates the line lock mechanism.

The operation of the margin block and release assentblywhich is operated by a margin release key, an'd the.- manner in which the extension 57 operates to control the l carriage escapement, which actuates the line lock mechanism, is well known in the art and therefore need not be described herein.

The carriage 1 is released from the escapement mech- 38 and 42 in such a manner that a control rail key and any escapement key 58 may be operated simultaneously by a single finger. The operator, therefore, may release the carriage from the escapement mechanism to permit free slidable movement of the carriage to effect the position at which the margin stops are to be set, and to shift the control rails to position the margin stops at the proper place, all by the simultaneous operation of the two keys by a single finger. The keys S8 have a rounded upper surface extending from front to rear, the keys S8 being in alignment with the margin set keys 38 and 42 and at approximately the same height to provide for the simultaneous single finger operation of both keys.

Each margin sto-p assembly 13 and 14 is provided with an integral -upstanding tab 59 which is of sufficient length to extend a predetermined distance above the upper edge .of the paper holder 4 so that a tab 59 will be visible by the operator from the front of the machine. The tabs 59 are visible against the graduations 9 of the scale 8, with the straight edge 60 of the tabs coinciding with a graduation. The operator therefore, may know at all times, by a swift glance, the exact location of a margin stop assembly with respect to the graduations 9 on the scale 8. Also, the operator sees the location of the stops 59 with respect to the paper table and the marginal edge of the paper guide 5.

The margin stops may be shifted to proper position manually by exerting a pressure against the two parts 44 and 47, or they may be positioned automatically by means of their respective springs upon the depression of a margin set key 38 or 42, the margin stop assemblies being pulled to their marginal positions at the locations originally set by the carriage in the usual conventional manner.

The tabs 59, being freely visible against the graduations 9 of the scale 8, permit the operator to know the exact position where the margin stops are to be set. The escapement key is depressed, freeing the carriage to a position where the tabs are to be set, and then without changing the position of the operators hand, the margin set key may be automatically brought to the set position, and as the finger is released, the carriage will again be in operation with the escapement with the margin stops in margin setting position.

VIn additionto the automatic setting of the margin setting of the stops, there is the manual operation available. To set the mar-gin stops manually, all that is required is that the sides of the margin stops be squeezed to free the stops fromthe dentated bar and then shifted manually until a tab is in proper position with respect to a graduation on the scale. The arrangement of the visible tabs on the stops, not only indicates to the operator where the stops are to be positioned, but also lets the operator know at all times where the margin stops actually are positioned. It is easy, therefore, for the operator to know where the margin stops are to be set for placing the margin on the sheet of paper, as well as seeing the actual stops at the position set according to the graduations on the scale 8. The graduations show the space at each side of the sheet where the typing is to begin. The use yand purpose of the marginal stop assemblies is well known in the art, and therefore, further detailed description of the operation need not be made.

The invention provides simple and effective means for effecting operation of the margin stop assemblies which may be either manually or automatically set as desired, and the provision of a separate spring for each margin stop assembly permits for positive, easy, eicient and silent operation. The location of the scale 8, and the provision of sight tabs 59 extending above the upper edge of the paper holder and viewable against the scale 8, as well as the specific construction and arrangement of the marginal stop assemblies themselves and their manner of operation in connection with the control rails provides for quick, easy and accurate means to stop the carriage.

Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fall fairly within the scope of the following claims.

The invention is claimed as follows:

l. In margin regulator mechanism, the combination with a typewriter including a movable carriage and a fixed stop post, of a rack bar mounted on the carriage, a pair of margin stop assemblies disposed for longitudinal sliding movement on the rack bar, an oscillatory detent member mounted on each stop assembly, a compression spring associated with each detent member for urging the detent member into a stop securing position on the rack bar, a separate spring attached to each stop assembly tending to slide the stops in opposite directions on the rack bar toward said fixed stop post, shiftable control rails engageable with the detent member of each assembly, said control rails extending longitudinally along said rack bar, one extending outwardly from one end of said rack bar and arranged to operate the release means of one stop assembly and the other extending outwardly from the other end of said rack bar and arranged to operate the release means of the other stop assembly, means normally retaining the control rails in elevated non-tripping position, and a key attached to the outwardly extending end of each control rail whereby the control rails may be actuated to a stop releasing position from a remote operating position.

2. 1n a typewriter having a movable carriage and a stop member, a margin regulator mechanism comprising a rack bar on the carriage, a pair of margin stop assemblies mounted on said bar for slidable movement thereon, a pulley mounted on each end of said carriage, a first coiled tension spring having one end connected to one stop as-l sembly and trained over one of said pulleys with the free end of said spring connected to a rigid part ofthe carriage, a second coiled tension spring having one end connected to the other stop assembly and trained over the other of said pulleys with the free end of the second spring connected to a rigid part of the carriage, a pivotally mounted detent for each assembly, spring means to urge the detent into a slot in the rack bar, means manually operatedto release a detent from the rack bar, and a downwardly and inwardly movable control rail adjacent each assembly to move a detent of an assembly out of a slot when a control rail is operated.

3. In a typewritter having a movable carriage and a stop member, a margin regulator mechanism comprising a rack bar on the carriage, a pair of margin stop assemblies mounted on said bar for slidable movement thereon, a pulley mounted on each end of said carriage, a first coiled tension spring having one end connected to one stop assembly and trained over one of said pulleys with the free end of said spring connected to a rigid part of the carriage, a second coiled tension spring having one end connected to the other stop assembly and trained over the other of said pulleys with the free end of the second spring connected to a rigid part of the carriage, a pivotally mounted detent for each assembly, a pivoted detent lever carrying the detent, spring means for each assembly to urge the detent into a slot of the rack bar, a control rail positioned above each assembly, and a key to operate the control rail, said control rail being constructed and arranged to move downwardly to engage the detent lever and shift the lever 8 and raise the detent out of a slot when the key is depressed. r

In a typewriter having a movable carriage and a stop member, a margin regulator mechanism comprising a rack bar on the carriage, a pair of margin stop assemblies mounted on said bar for slidable movement thereon, a pulley mounted on each end of said carirage, a rst coiled tension spring having one end connected to one stop assembly and trained over one of said pulleys with the free end of said spring connected to a rigid part of the carriage, a second coiled tension spring having one end connected to the other stop assembly and trained over the other of said pulleys with the free end of the second spring connected to a rigid part of the carriage, a pivotally mounted detent for each assembly, a pivoted detent lever carrying the detent, spring means for each assembly to urge the detent into a slot of the rack bar, a control rail for each as-y sembly, a fixed bar adjacent the control rails, said rails each having inclined slots, pins on the fixed bar passing through said slots, a key lever to shift each control rail, and means including the detent lever to raise the detent out of a slot when a control rail is shifted.

5. In a typewriter having a movable carriage and a stop member, a margin regulator mechanism comprising a rack bar on the carriage, a pair of margin stop assemblies mounted on said bar for slidable movement thereon, a pulley mounted on each end of said carriage, a first coiled tension spring having one end connected to one stop assembly and trained over one of said pulleys with the free end of said spring connected to a rigid part of the carriage, a second coiled tension spring having one end connected to the other stop assembly and trained over the other of said pulleys with the free end of the second spring connected to a rigid part of the carriage, a pivotally mounted detent for each assembly, a pivoted detent lever carrying the detent, spring means for each assembly to urge the detent into a slot of the rack bar, a control rail for each assembly, a fixed bar adjacent the control rails, said rails each having inclined slots, pins on the xed bar passing through said slots, a key lever to depress each control rail, means including the detent lever to raise the detent out of a slot when a control rail is depressed, and spring means connected to the control rails to urge said rails in a predetermined direction.

6. In a typewriter having a movable carriage and a stop member, a margin regulator mechanism comprising a rack bar on the carriage, a pair of margin stop assemblies mounted on said bar for slidable movement thereon, a pulley mounted on each end of said carriage, a rst coiled tension spring having one end connected to one stop assembly and trained over one of said pulleys with the free end of said spring connected to a rigid part of the carriage, a second coiled tension spring having one end connected to the other stop assembly and trained over the other of said pulleys with the free end of the second spring connected to a rigid part of the carriage, a pivotally mounted detent for each assembly, a pivoted detent lever carrying the detent, spring means for each assembly to urge the detent into a slot of the rack bar, a control rail for each assembly, a fixed bar adjacent the control rails, said rails each having inclined slots, pins on the fixed bar passing through said slots, a key lever to depress each control rail, means including the detent lever to raise the detent out of a slot when a control rail is depressed, spring means connected to the control rails to urge said rails in a predetermined direction, a paper holder on the carriage arranged forwardly of the margin stop assemblies and concealing said assemblies, graduated scales on the paper holder at each end thereof, and a projection on each assembly and extending above the upper edge of the paper holder so that the positions of the assemblies are visible with respect to the scales on the holder.

7. In artypewriter carriage having a slotted rack bar, a margin stop assembly comprising a shoe slidably mounted on said bar, a rigid arm connected to said shoe, a second arm pivotally connected to` the -rigid arm, a detent lever pivotally connected to said shoe, a detent on the detent lever and adapted to engage a slot in the rack bar, a finger on the second arm Varranged beneath the detent lever to move the'detent out of a slot when the second arm is moved on its pivot, spring means to urge the detent lever in a predetermined direction to maintain the detent in a slot in the rack bar, said second arm moving the linger to raise the detent when the second arm is'operated, a coiled spring having oneen'd connected to said assembly and its other end connected to a rigid part of the carriage, and a pulley mounted on said carriage over which the coil tension spring is trained.

8. In a typewriter carriage having a slotted rack bar, a margin stop assembly comprising a shoe slidably mounted on said bar, a rigid arm connected to said shoe, a second arm pivotally connected to the rigid arm, a detent lever pivotally connected to said shoe, a detent on the detent lever and adapted to engage a slot in the rack bar, a finger on the second arm arranged beneath the detent lever to move the detent out of a slot when the second arm is moved ron Iits pivot, spring means to urge the detent lever in a predetermined direction to maintain the detent in a slot in the rack bar, said second arm moving the iinger to raise the detent when the second arm is operated, a coiled spring having one end connected to said assembly and its other end connected to a rigid part of the carriage, a pulley mounted on said carriage over which the coil tension spring is trained, and a depressible control rail adjacent the second arm and operating the detent arm to raise the detent out of a slot when the control rail is depressed.

9. In a typewriter carriage having a slotted rack bar, a margin stop assembly comprising a shoe slidably mounted on said bar, a rigid arm connected to said shoe, a second arm pivotally connected to the rigid arm, a detent lever pivotally connected to said shoe, a detent on the detent lever and adapted to engage a slot in the rack bar, a iinger on the second arm arranged beneath the detent lever to move the detent out of a slot when the second arm is moved on its pivot, spring means to urge the detent lever in a predetermined direction to maintain the detent in a slot in the rack bar, said second arm moving the nger to raise the detent when the second arm is operated, a coiled spring having one end connected to said assembly and its vother end connected to a rigid part of the carriage, a pulley mounted on said carriage over which the coil tension spring is trained, a roller on one end of the detent lever, a depressible control rail above the roller,

said rail pressing the roller to move the detent lever and lift the detent out of a slot in the rack bar, and spring means to urge the control rail upwardly.

10. In margin stop mechanism, the combination with a typewriter having a movable carriage and a iiXed stop member, of a type roller on the carriage, a member fastened to the carriage behind the roller and extending from end-to-end of the carriage, said member having a scale thereon extending from end-to-end of the member, said scale including graduations and numeral indicia on the member, a rack bar mounted on the carriage, margin stop assemblies on the rack bar, means associated with each margin stop assembly for engaging the rack bar in a stop position, first releasing means associated with each margin stop assembly for releasing each margin stop assembly from the stop position on the rack bar, second releasing means associated with each margin stop assembly for releasing each margin stop assembly from the rack bar, each said second releasing means including a control rail extending from adjacent each margin stop assembly to an end of the carriage whereby each margin stop assembly may be released from the stop position by operating the appropriate control rail from the end of the carriage, and projecting tabs on the stop assemblies extending above the roller and positioned immediately adjacent said scale, whereby the location of the margin stop assemblies isvisibleby` anfoperator for determining the position vat which the said stop assemblies are to be setr` writer carriage comprising margin stops slidably mounted on a part carried by the carriage, means associated with each margin stop assembly for engaging the carriagecarried part in a stop position, rst releasing means associated with each margin stop assembly for releasing each margin stop assembly from the stop position on the carriage-carried part, second releasing means associated with each margin stop assembly for releasing each margin stop assembly from the carriage-carried part, each second releasing means including a control rail extending from each margin stop assembly to an end of the carriage whereby each margin stop assembly may be released from the stop position by operating the appropriate control rail from the end of the carriage, a member fastened to the carriage and extending across the carriage adjacent the carriage ends, an elongated scale on said member, said scale including graduations and numeral indicia, and projections visible by an operator on said stops and cooperating with said graduations whereby the operator may determine the position to which stops are to be set and the position where stops are set.

l2. In margin regulator mechanism, the combination with a typewriter including a movable carriage and a stop member, of a rack bar mounted on the carriage, a pair of margin stop assemblies disposed for longitudinal sliding movement on the rack bar, a detent member mounted on each stop assembly and adapted to engage the rack bar, releasable means to release the detent member from the stop bar to permit the stop assemblies to slide on the rack bar, shiftable control rails to operate said release means of each assembly, said control rails extending longitudinally along said rack bar, one extending outwardly from one end of said rack bar and arranged to operate the release means of one stop assembly and the -other extending outwardly from the other end of said rack bar and arranged to operate the release means of the other stop assembly, means normally retaining a control rail in a predetermined position, and a key on the outer end of each control rail to actuate said control rail to a stop releasing position from a remote operating position.

13. In margin regulator mechanism, the-combination with a typewriter including a movable carriage and a stop member, of a rack bar mounted on the carriage, a pair of margin stop assemblies disposed for longitudinal sliding movement on the rack bar, a detent member mounted on each stop assembly and adapted to engage the rack bar, releasable means to release the detent member from the rack bar to permit the stop assemblies to slide on the rack bar, shiftable control rails to operate said release means of each assembly, said control rails extending longitudinally along said rack bar, one extending outwardly from one end of said rack bar and arranged to operate the release means of one stop assembly and the other extending outwardly from the other end of said rack bar and arranged to operate the release means of the other stop assembly, means normally retaining a control rail in a predetermined position, a key on the outer end of each control rail to actuate said control rail to a stop releasing position from a remote operating position, and an escapement key on each side of the carriage and arranged adjacent a key for a control rail whereby both keys may be operated by one linger of the operator simultaneously.

14. In a typewriter having a movable carriage, a margin regulator mechanism comprising margin stop assemblies slidable on a part of the carriage, control rails to release said stop assemblies for slidable movement, said rails having elongated inclined slots adjacent their outer ends, and pins fastened to the carriage and receivable in said slots.

said rails having elongated inclined slots adjacent their' outer ends, pins fastened to the carriage and receivable in said slots, and a key on at least one end of each control rail to operate said rail.

References Cited in the le of this patent UNITED STATES PATENTS Steiger Apr. 7, 1896 Scherer Apr. 7, 1931 Woodne July 4, 1933 Hart July 16, 1940 Prezioso Nov. 24, 1942 Brumhill Apr. 19, 1949 Schremp et al. Oct. 2, 1951 

